Kudos on a great start!
One of my simple joys is to look at a piece of land and imagine how I would work with it. Each piece is different and each piece changes while you're looking and working it.
One thing I've learned is to be patient. I can't list how many "good ideas" I've had that I am so thankful I never acted on. This is especially true with earth works, like digging a pond. It requires much consideration from many points of view.
I've got a small creek on my property that I REALLY want to back up into a small pond that I need to excavate. I would not divert the creek, just flow it into and out of the as yet non-existent pond. Originally I was thinking BIG, but with more thought I've scaled back the size of the pond. I'm sure it will change a lot more before the excavator goes to work.
Keep us posted on your lessons learned; they're what's important.
It has been fun figuring out where each piece fits into our property. There have been many changes from what we envisioned when we bought it. We waited a year before taking on big projects that are hard to change, so that we could consider all the factors. I've been eying this pond location for a while and it keeps looking better. Most of the rainwater funnels through this spot before flowing down our property.
I'm not sure what kind of topology your place has but I've found some good tools online.
They may or may not help you but I'll pass them along.
If you have any favorite links please share with us too.
But most of all have fun!